If mold has grown on the jar lid, we suggest you discard
the food. Mold can actually cause loss of seal and
recontamination of food. If mold is growing elsewhere on
the outside of the jar, carefully wash the jar with hot
soapy water, rinse and dry it. Check out your storage
area. Mold growing on jars indicates that it may be too
damp, and/or that food residue was left on the jars.
Before storage, always remove jar rings, wash, rinse and
dry jars and store them in a cool, dry, dark area.